Design and Characterization of a Sharp GaAs/Zn(Mn)Se Heterovalent Interface: A Sub-Nanometer Scale View

Area of Science:

• Materials Science
• Semiconductor Physics
• Nanotechnology

Background:

• Investigating magnetic semiconductor interfaces is crucial for spintronic devices.
• Understanding dopant distribution at heterovalent interfaces presents significant challenges.

Purpose of the Study:

• To precisely map the distribution of manganese (Mn) impurities at the GaAs/Zn(Mn)Se heterovalent interface.
• To correlate Mn distribution with growth conditions and annealing treatments.
• To assess the feasibility of creating sharp interfaces for high-quality magnetic semiconductor devices.

Main Methods:

• Combined Cross-Section Scanning Tunnel Microscopy (X-STM), Atom Probe Tomography (APT), and Secondary Ions Mass Spectroscopy (SIMS).
• Achieved sub-nanometer resolution and high sensitivity for impurity analysis.
• Investigated the impact of growth parameters and post-growth annealing.

Main Results:

• Manganese (Mn) diffusion into the Gallium Arsenide (GaAs) layer is significantly suppressed.
• Mn atoms undergo substantial redistribution within the Zinc Selenide (ZnSe) layer.
• Distribution is influenced by growth conditions and annealing processes.

Conclusions:

• A sharp interface between magnetic semiconductor Zn(Mn)Se and high-quality GaAs can be fabricated.
• Low dopant concentration and good optical properties are achievable.
• The study provides insights into controlling magnetic impurity distribution at heterovalent interfaces.